Excel Web Access Graphs Showing Gray Color

In my SharePoint2007 environment I use Excel Web Access to show the Excel charts with-in SharePoint site. The issue was , all Excel Web Access Charts started showing only gray color . I did lot of search on Google but could not find any solution.

Solution: I ran "sharepoint Technologiesand Configuration wizard" on my SharePoint servers and rebooted them. That resolved my issue. I hope this helps some else in future.